High peak power solid-state laser and high power pulsed amplifiers, which are characterized by a relatively high gain, typically need a means of defeating the naturally occurring transverse gain that can lead to losses from amplified spontaneous emission (ASE). Background information on such deleterious ASE can be found in “Fluorescence Amplification and Parasitic Oscillation Limitations in Disk Lasers”, by J. B. Trenholme, NRL Memorandum Rep. 2480, July, 1972; J. E. Swain, et al., J. Appl. Phys., 40, p. 3973 (1969); and J. M. McMahon et al., IEEE J. Quantum Electron. QE-9, p. 992 (1973).
A technique that has been utilized to suppress ASE and to suppress the onset of parasitic oscillations involves bonding a designed absorbing material to the edges of the gain medium (i.e., an edge cladding). If the index of refraction of the bonded absorbing material substantially matches that of the gain medium, a substantial portion of the ASE is coupled out of the gain media and into the absorbing material before it can build sufficiently to depopulate the excited state and thus reduce or clamp the gain. Despite the benefits provided by edge claddings, there is a need in the art for improved methods and systems for gain isolation.